This invention relates to determining the nature of a minute particle or sample through infrared detection techniques, and in particular to a method and apparatus for determining the nature of the sample by heating the sample over a range of infrared frequencies and measuring the resultant infrared absorption of the sample.
There are known methods for determining the molecular characterization, and therefore nature, of small samples of matter. Standard infrared spectrometric methods have been well know for quite some time, but are not readily useable for very small particles, and therefore not available for determining the molecular nature, as opposed to the elemental nature, of a particle. Other methods of spectrometry, such as the Raman method, are known and used to determine the characteristics of particles as small as 10 microns, with difficulty at that small size. The Raman method suffers the deficiency that the number of reference spectra for the Raman method is not nearly as large as the number of reference spectra available when using standard infrared spectrometric methods. In addition, when using the Raman method, large amounts of energy are employed. When organic samples are studied, the Raman method cannot be employed since live cells would be destroyed.